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Technical Paper

A 3D User and Maintenance Manual for UAVs and Commercial Aircrafts Based on Augmented Reality

2015-09-15
2015-01-2473
Traditional User/Maintenance Manuals provide useful information when dealing with simple machines. However, when dealing with complex systems of systems and highly miniaturized technologies, like UAVs, or with machines with millions of parts, a commercial aircraft is a case in point, new technologies taking advantage of Augmented Reality can rapidly and effectively support the maintenance operations. This paper presents a User/Maintenance Manual based on Augmented Reality to help the operator in the detection of parts and in the sequence to be followed to assemble/disassemble systems and subsystems. The proposed system includes a handheld device and/or an head mounted display or special goggles, to be used by on-site operators, with software management providing data fusion and overlaying traditional 2D user/maintenance manual information with an augmented reality software and appropriate interface.
Journal Article

A Comparison of Full Scale Aft Cavity Drag Reduction Concepts With Equivalent Wind Tunnel Test Results

2013-09-24
2013-01-2429
Comparison studies have been conducted on a 1:16th scale model and a full scale tractor trailer of a variety of sealed aft cavity devices as a means to develop or enhance commercial drag reduction technology for class 8 vehicles. Various base cavity geometries with pressure taps were created for the scale model. The studies confirmed that length has an important effect on performance. The interaction of the boat-tailed aft cavity with other drag reduction devices, specifically side skirts, was investigated with results showing no discernable drag performance interaction between them. Overall, the experiments show that a boat-tailed aft cavity can reduce the drag up to 13%. Full-scale tests of a commercially derived product based on these scale tests were also completed using SAE Type II testing procedures. Full-scale tests indicated a fuel savings of over 6.5%.
Technical Paper

A Mesh Based Approach for Unconventional Unmanned Airship Added Masses Computation

2013-09-17
2013-01-2191
Added masses computation is a crucial aspect to be considered when the density of a body moving in a fluid is comparable to the density of the fluid displaced: added mass can be defined as the inertia added to a system because an accelerating or decelerating body displaces some volume of neighboring fluid as it moves through it. The motion of vehicles like airships and ships can be addressed only by keeping into account the effect of added masses, while in case of aircrafts and helicopters this contribution is usually neglected. Lighter Than Air flight simulation, unmanned airships flight control system, airships flight dynamics are typical applications in which added masses are fundamental to achieve an effective and realistic modeling. A panel based method using the mesh of an airship external shape is developed to account for the added massed.
Technical Paper

Active Flow and Aeroelastic Control of Lifting Surfaces Using Synthetic Jet Actuators

2007-09-17
2007-01-3920
Active flow control devices such as zero-net-mass-flux actuators have broad aeronautical applications. Among them, low power and lightweight Synthetic Jet Actuators can be used to improve the performance of flight vehicles, providing load alleviation capabilities, expanding their flight envelope, and preventing catastrophic failure by aeroelastic instabilities. Numerical and experimental investigations are proving that SJAs are effective in actively altering the boundary layer; the effect of the momentum exchange due to the SJAs leads to a rearrangement of streamlines, a virtual aerodynamic shaping that enable changes in the aerodynamics forces acting on the lifting surfaces. This paper discusses development aspects that the authors have been conducting on the topic with applications to load alleviation and flutter suppression for aircraft wings.
Technical Paper

Airship and Hot Air Balloon Real Time Envelope Shape Prediction through a Cloth Simulation Technique

2015-09-15
2015-01-2578
The flight simulation of airships and hot air balloons usually considers the envelope geometry as a fixed shape, whose volume is eventually reduced by ballonets. However, the dynamic pressure or helium leaks in airships, and the release of air to allow descent in hot air balloons can significantly change the shape of the envelope leading to potential dangerous situations. In fact, in case of semi-rigid and non-rigid airships a reduction in envelope internal pressure can reduce the envelope bending stiffness leading to the loss of the typical axial-symmetric shape. For hot air balloons thing goes even worse since the lost of internal pressure can lead to the collapsing of the balloon shape to a sort of vertically stretched geometry (similar to a torch) which is not able to sustain the attached basket and its payload.
Technical Paper

An Integrated Software Environment for UAV Missions Support

2013-09-17
2013-01-2189
This paper describes the design and development of a virtual environment conceived to support flight operations of an Unmanned Air Vehicle (UAV) used for wind mapping in the proximity of existing or planned wind farms. The virtual environment can be used in pre-flight briefings aiming to define a trajectory from a list of waypoints, to change and eventually re-plan the mission in case of intersection with no fly zones, to simulate the mission, and to preview images/videos taken from the UAV on-board cameras. During flight, the tool can be used to compute the wind speed along the trajectory by analyzing the data streaming from the UAV. The integration of Augmented Reality (AR) techniques in the flight environment provides assistance in remotely piloted landings, and allows visualizing flight and environmental information that are critical to the mission.
Technical Paper

CFRP Crash Absorbers in Small UAV: Design and Optimization

2015-09-15
2015-01-2461
The high number of hull losses is a main concern in the UAV field, mostly due to the high cost of on-board equipment. A crashworthiness design can be helpful to control the extent and position of crash impact damage, minimizing equipment losses. However, the wide use of composite materials has recently put the accent on the lack of data about the behavior of these structures under operative loads, such as the crash conditions. This paper presents the outcome of a set of tests carried out to achieve a controlled crush of UAV structures, and to maximize the Specific Energy Absorption. In this work, a small-scale experimental test able to characterize the energy absorption of a Carbon-fiber-reinforced polymer under compression was developed introducing self-supporting sinusoidal shape specimens, which avoid the need for complex anti-buckling devices.
Technical Paper

Design and Experimental Investigation of a Small UAV

2009-11-10
2009-01-3166
In this paper two different tools have been applied to the problem of designing a small UAV. With these tools a parametric study of wing configuration and sizing was performed. The focus of this study was to optimize range and endurance of the UAV during a particular flight mission. The two numerical analysis tools applied to the UAV wing design were developed for widely different analysis problems. The first tool, the aircraft DATCOM was developed for the preliminary design analysis of manned aircraft and will be used to perform parametric modeling and geometry optimization. The Projectile Rocket Ordinance Design and Analysis System (PRODAS®) software was developed for ballistic projectiles and will be used for 6 DOF fixed plane trajectory simulation of the developed UAV concepts. While the scale of the UAV selected does not match well with the DATCOM software, the mission requirements and analysis format of the software is advantageous.
Technical Paper

Design, Manufacturing, and Testing of a Research Unmanned Aerial Vehicle

2011-10-18
2011-01-2721
This paper details the novel manufacturing processes for an experimental, all-composite, research UAV to be used by Clarkson University. Discussions will include an in depth report on the selection of materials, manufacturing methods, and the implementation and results of the fabrication procedures for the structural components along with the challenges of constructing an aircraft capable of meeting multiple FAA regulatory requirements.
Technical Paper

Design, Optimization, Performances and Flight Operation of an All Composite Unmanned Aerial Vehicle

2013-09-17
2013-01-2192
Unmanned Aerial Vehicles (UAVs) provide the ability to perform a variety of experimental tests of systems and unproven research technologies, including new autopilot systems and obstacle avoidance capabilities, without risking the lives of human pilots. This paper describes the activities of design, optimization, and flight operations of a UAV conceived at Clarkson University (USA) and equipped to perform wind speed measurements to support wind farmsite planning. The UAV design has been assisted and validated by the use of an automatic virtual environment for the assisted design of civil UAVs. This tool can be used as a “computing machine” for civil UAVs. The operator inputs the mission profile and other generic parameters and data about performance, aerodynamics, and weight breakdown are extracted. A mathematical model of the UAV for flight simulation and its dynamic computations, along with automatic drawing is also produced.
Technical Paper

Ethanol to Gasoline Ratio Detection via Time-Frequency Analysis of Engine Acoustic Emission

2012-09-10
2012-01-1629
In order to reduce both polluting emissions and fuel costs, many countries allow mixing ethanol to gasoline either in fixed percentages or in variable percentages. The resulting fuel is labeled E10 or E22, where the number specifies the ethanol percentage. This operation significantly changes way the stoichiometric value, which is the air-to-fuel mass ratio theoretically needed to completely burn the mixture. Ethanol concentration must be correctly estimated by the Engine Management System to optimally control exhaust emissions, fuel economy and engine performance. In fact, correct fuel quality recognition allows estimating the actual stoichiometric value, thus allowing the catalyst system to operate at maximum efficiency in any engine working point. Moreover, also other essential engine control functions should be adapted in real time by taking into account the quality of the fuel that is being used.
Technical Paper

Experimental Methods for the Characterization of the Static and Dynamic Stability of a Spinning Body

2011-10-18
2011-01-2735
Newly developed technologies are enabling the design of Unmanned Aerial Vehicles (UAVs) and Micro Air Vehicles (MAVs) with heretofore unrealized capabilities. A tube-launch MAV would allow the increased flexibility to launch an aircraft rapidly without need for a runway or complex launching system, either from a vehicle, installation, or as a man-portable device. The MAV would fill the diameter of the launch tube and deploy aerodynamic lifting and control surfaces after launch. In order to deploy the lifting surfaces the MAV must be capable of deploying control surfaces, negating any tube-imparted roll rate, and developing an optimal flight attitude automatically. An experimental method was developed to characterize the aerodynamics and stability of a blunt body spinning under conditions of roll rate decay in the Clarkson University High Speed Wind tunnel. This method is to be used to evaluate the development of an active roll rate control system for spinning projectiles.
Technical Paper

Image Processing Based Air Vehicles Classification for UAV Sense and Avoid Systems

2015-09-15
2015-01-2471
The maturity reached in the development of Unmanned Air Vehicles (UAVs) systems is making them more and more attractive for a vast number of civil missions. Clearly, the introduction of UAVs in the civil airspace requiring practical and effective regulation is one of the most critical issues being currently discussed. As several civil air authorities report in their regulations “Sense and Avoid” or “Detect and Avoid” capabilities are critical to the successful integration of UAV into the civil airspace. One possible approach to achieve this capability, specifically for operations beyond the Line-of-Sight, would be to equip air vehicles with a vision-based system using cameras to monitor the surrounding air space and to classify other air vehicles flying in close proximity. This paper presents an image-based application for the supervised classification of air vehicles.
Technical Paper

Modeling the Diesel Fuel Spray Breakup by Using a Hybrid Model

1999-03-01
1999-01-0226
Diesel engine CFD simulation is challenged by the need to improve the accuracy in the spray modeling due to the strong influence played by spray dynamics on evaporation rate, flow field, combustion process and emissions. This paper aims to present a hybrid model able to describe both primary and secondary breakup of high-dense high-pressure sprays. According to this approach, the model proposed by Huh and Gosman is used to compute the atomization of the liquid jet (primary breakup) while a modified version of the TAB model of O'Rourke and Amsden is used for the secondary breakup. The atomization model considers the jet turbulence at the nozzle exit and the growth of unstable wave on the jet surface. In order to validate the hybrid model, a free non-evaporating high-pressure-driven spray at engine like conditions has been simulated. The accuracy of the breakup time evaluation has been improved by tuning the TAB constant Ck according to the Pilch's experimental correlations.
Technical Paper

Multicycle Simulation of the Mixture Formation Process of a PFI Gasoline Engine

2012-06-01
2011-01-2463
The mixture composition heavily influences the combustion process of Port Fuel Injection (PFI) engines. The local mixture air-index at the spark plug is closely related to combustion instabilities and the cycle-by-cycle Indicated Mean Effective Pressure (IMEP) Coefficient of Variation (CoV) well correlates with the variability of the flame kernel development. The needs of reducing the engine emissions and consumption push the engine manufactures to implement techniques providing a better control of the mixture quality in terms of homogeneity and variability. Simulating the mixture formation of a PFI engine by means of CFD techniques is a critical issue, since involved phenomena are highly heterogeneous and a two phase flow must be considered. The aim of the paper is to present a multi-cycle methodology for the simulation of the injection and the mixture formation processes of high performance PFI engine, based on the validation of all the main physical sub-models involved.
Technical Paper

New Unconventional Airship Concept by Morphing the Lenticular Shape

2015-09-15
2015-01-2577
The aim of this paper is to develop a new concept of unconventional airship based on morphing a lenticular shape while preserving the volumetric dimension. Lenticular shape is known to have relatively poor aerodynamic characteristics. It is also well known to have poor static and dynamic stability after the certain critical speed. The new shape presented in this paper is obtained by extending one and reducing the other direction of the original lenticular shape. The volume is kept constant through the morphing process. To improve the airship performance, four steps of morphing, starting from the lenticular shape, were obtained and compared in terms of aerodynamic characteristics, including drag, lift and pitching moment, and stability characteristics for two different operational scenarios. The comparison of the stability was carried out based on necessary deflection angle of the part of tail surface.
Technical Paper

Rapid Prototyping as a Tool to Support Wind Tunnel Testing of Unconventional Unmanned Airships

2013-09-17
2013-01-2193
Scaled models are often used to check the aerodynamic performance of full scale aircraft and airship concepts, which have gone through a conceptual and preliminary design process. Results from these tests can be quite useful to improve the design of unconventional airships whose aerodynamics might be quite different from classical configurations. Once the airship geometry has been defined, testing is required to acquire aerodynamic data necessary to implement the mathematical model of the airship needed by the flight control system to develop full autonomous capabilities. Rapid prototyping has the great potential of playing a beneficial role in unconventional autonomous airship design similarly to the success obtained in the design process of conventional aircrafts.
Technical Paper

Structural and Manufacturing Considerations for a Research Unmanned Aerial Vehicle

2009-11-10
2009-01-3196
This paper discusses the various factors that were addressed in the planning process for the design and construction of an unmanned aerial vehicle (UAV) destined for use as a multirole research aircraft for Clarkson University. Details related to mission requirements, cost, construction materials, manufacturing methods, and regulatory requirements will be discussed. The resulting airframe, structure, manufacturing, and control system plan of action will be laid out. An overview of anticipated FAA regulations will be presented, and the need to design for conformity to said regulations addressed. Emphasis will be placed on design and manufacturing decisions relating to the extensive use of composite materials throughout the aircraft.
Technical Paper

Superheated Sprays of Alternative Fuels for Direct Injection Engines

2012-04-16
2012-01-1261
Alternative and oxygenated fuels are nowadays being studied in order to increase engine efficiency and reduce exhaust emissions and also to limit the automotive industry's economical dependency from crude oil. These fuels are considered more ecological compared to hydrocarbons because they are obtained using renewable sources. Fuels like anhydrous/hydrous ethanol, methanol or alcohol/gasoline blends which are injected in liquid form must vaporize quickly, especially in direct injection engines, therefore their volatility is a very important factor and strongly depends on thermodynamic conditions and chemical properties. When a multi-component fuel blend is injected into a low pressure environment below its saturation pressure, a rapid boiling of the most volatile component triggers a thermodynamic atomization mechanism. These kinds of sprays show smaller droplets and lower penetration compared to mechanical break up.
Technical Paper

System Identification from GVT and Taxiing of an Unmanned Aerial Vehicle

2013-09-17
2013-01-2190
The modal parameters of an aircraft structure are currently estimated from ground vibration tests (GVT). These tests are carried out on ground in order to estimate the frequency response functions first and then the modal parameters. Such estimates require one or more shakers to excite the structure together with simultaneous measurements of both the input and the output signals. Recent developments in operational modal analysis allowed such modal identification from the measurements of the output responses only, provided that the unmeasurable excitation is practically a white noise stochastic input in the frequency range of interest and is randomly exciting the different parts of the structure. In this paper the effects of the different test setup on the modal parameter estimates will be presented. Both input-output based experimental modal analysis and operational modal analysis are performed on an Unmanned Aerial Vehicle, the Clarkson University Golden Eagle.
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